MUMBAI, July 23 -- A US law firm has opened an investigation into whether HDFC Bank violated US federal securities laws, extending scrutiny of the lender beyond India after allegations around internal payments and governance triggered a sharp fall in its US-listed shares.

US-based Glancy Prongay & Rotter LLP said it is examining whether HDFC Bank issued materially misleading business information to investors or otherwise violated federal securities laws. The announcement, published on global press release distribution platform Business Wire on 22 July, urged investors who suffered losses to contact the firm.

HDFC Bank's American Depositary Shares trade on the New York Stock Exchange under the ticker HDB, making the bank subject to US se...